Elementary is heading to Sherlock Holmes’ old stomping grounds.

The CBS drama opens its sophomore season with Sherlock (Jonny Lee Miller) and partner/apprentice Joan Watson (Lucy Liu) traveling to London to help track down one of Sherlock’s old mentors, Inspector Lestrade (Sean Pertwee), and to investigate an unsolved mystery. It’s there that Sherlock is reunited with his estranged brother, Mycroft (Rhys Ifans).

After a season filled with twists, turns and unexpected reveals, executive producer Rob Doherty admits to The Hollywood Reporter that it took some time to have all the key players fully grasp what Elementary was. And because of the ambitious season opener, the writers didn’t have a significant amount of time to reflect on the year that was. Even so, Doherty is confident in how the season two kicks off.

“Season two has been intense, but great,” he tells THR. “It’s quite an undertaking shooting your premiere in another country, but obviously it was an incredible opportunity.”

Doherty jumped on the phone with THR to chat about the London premiere, meeting Sherlock’s brother Mycroft, balancing the procedural elements with the mythology and toying with the introduction of a new villain.

What did you take away from season one that helped in your approach to season two?

Over the first 12 episodes of last year, a lot of what we were trying to do was make sure everyone was on the same page — that the studio, the network, the actors, the writers, the producers are all seeing essentially the same thing when they look at the show. That sounds easier than it is. It takes some time and I think there were a handful of growing pains in the beginning. But around the middle of the season, we were able to identify everything we thought was working and everything that we thought needed some work. As we moved into the back half of the season, I dare say things went a little more smoothly. Coming into season two, it was really about applying everything we had learned in the second half of last year. There wasn’t really much of a break between seasons one and two, so for me and most of the writers, a lot of it has bled together.

What was the most difficult thing about filming in London?

It’s funny. This was hardly a difficulty, but the weather was unusually pleasant. You hear you’re going to London, and you assume you’re going to have fog and clouds — a very traditional British atmosphere — but it was some of the loveliest weather the city had had in a long time. We were close to 80 [degrees] every day. I feel like what we ended up with is more of a postcard, if you will.

Because you’re opening a whole season in a completely different location, was there a conscious decision to differentiate the London world from the New York City setting?

It was a little disorienting being away from the stages [in New York] to the degree that we were. Every single day in London was a location day. Our show has a certain rhythm, and we absolutely rely on the domestic side of the [Sherlock/Watson] partnership. We go home with Holmes and Watson at night and it was definitely trickier to do that in London when you don’t have the brownstone, you don’t have the police station. It was a challenge when it came to structuring the show and then figuring out a way to produce it, but again, it was a fun logistical problem to have to solve.

How close to the source material are you staying with the characters that we’ll be seeing this season?

With Inspector Lestrade, we felt we stayed close to the source material. In the books Lestrade was never described in a flattering matter. I believe the term was ferret-like, a bit of a glory seeker, he relied on help from Sherlock Holmes because he was more of a political animal and he was more than happy to take the credit for Sherlock’s deductions and victories. As far as introducing Lestrade in this episode, the question we kept asking ourselves is “What happens to a Lestrade when he loses his Holmes?” You would think that if he has grown accustomed to the kind of support a Sherlock Holmes can offer you, you’d be in for a rude awakening once he is gone. So, Inspector Lestrade at the top of the show has actually found himself in some pretty serious trouble, and Sherlock and Joan travel to London to try to assist him.

How close is Sherlock’s brother, Mycroft?

In the original books and stories, Mycroft is tall, overweight and allegedly as smart or smarter than his brother Sherlock. Mycroft only appears in two short stories and both times, he’s presented as this lazy, sloth-like individual. And while he may be as smart as Sherlock and as observant, he doesn’t have it in him to actually apply himself to anything. We didn’t think that sounded quite right for our Mycroft, but we did like the idea that Sherlock perceives him to be quite lazy, in that anyone who is not doing what Sherlock Holmes is doing is lazy and wasting his or her time. So he has a certain attitude about Mycroft. When we meet Mycroft in the premiere, we’ll discover that the brothers haven’t spoken for several years. They had a falling out and haven’t been in touch since. Things got so bad that Sherlock has never even mentioned that Mycroft existed to Joan, so it’s a surprise to her as well.

A lot was made about Watson being a female prior to the show airing. Did you have the Moriarty gender flip planned out at that point?

Our take on Moriarty was actually a part of the pitch that sold the show. It was always a target way off in the distance, and when I was pitching the show, I was looking forward to the challenge I had created for myself and the other writers. But yeah we always had that backstory. We enjoyed using the bulk of the season to build that mystery as to what actually happened to Sherlock in London, and how he bottomed out.

Did you have reservations about the Irene Adler/Moriarty reveal?

There was never any second-guessing only because we were always prepared to lose those people who just couldn’t wrap their heads around it. We knew there would absolutely be purists who would struggle with it, and I feel like some of them tuned out, but some of them were kind enough to give us a shot and stayed with us, and that’s been really gratifying. You’re right, there’s been so much clamor about it going in to our first season. There were a lot of preconceived notions, and it was very strange. It was absolutely an element of every interview that I did, that Lucy did, that Johnny did. Coming into season two, it’s just not a big deal anymore, and it’s nice because it was never supposed to be a big deal. I understand and anticipated a certain level of fascination with it or opposition to it, but now that we have an entire season under our belt, it just doesn’t seem to be as big a deal for most people and we’re grateful.

Now that Watson is no longer Sherlock’s official sober companion, how is their dynamic different?

You’re right, she hasn’t been his official companion in quite some time, but she has remained supportive of his recovery efforts. We’ll see in season two Sherlock is taking a little more ownership in that aspect of his life, but it doesn’t mean Joan no longer has a role to play. Day to day she’s more his partner than his companion, but she’ll always keep tabs on his progress. She’ll have the time to stop and talk through that struggle he has to deal with on a daily basis.

By the end of the season, Watson is studying to be a detective with Sherlock’s help. How does that evolve their partnership?

There’s still something of an education going on. The characters, just like us, have had a summer to practice and improve. As we come into season two, there’s a lot she has picked up from osmosis and there’s a lot she has picked up under his tutelage. Watson is holding her own quite nicely.

What can we expect to discover when we delve into her medical past?

There will be an episode early on in the season where we explore her past as a surgeon a little bit more. In the very first episode [last year], Sherlock deduced she’d made a mistake during surgery that cost a patient his life and that part of her past came up a few times overt the course of last year. In our first handful of episodes, we want to hit it a little more head on, get a few more of the details. Joan will cross paths with someone [played by Smash’s Jeremy Jordan] whose life was affected by that mistake.

Elementary is primarily a two-hander with Sherlock and Watson, but there is also a procedural element at play. How are you incorporating that world and those characters effectively this go-around?

There’s the same balance that we struck over the course of the first season. We never want to be an entirely procedural show, and I don’t think that we could be, because that’s not what the original Holmes and Watson were. That’s not what their franchise was. What’s great about writing for Holmes and Watson is you do have to go home with them at night and they have to have things to talk about, even if it seems mundane and even if it’s roommate stuff. The challenge for us is always finding new and interesting obstacles for them to attack on the character side of things. The cases are absolutely important and they dictate the structure of the show, but we want to make sure people are just as interested in the characters of Holmes and Watson as they are [Captain Thomas] Gregson [played by Aidan Quinn] and [Detective Marcus] Bell [Jon Michael Hill].

Will Gregson and Bell be incorporated into stories outside of the precinct?

What I can promise is in the first handful of episodes — maybe around the fourth or fifth episode — we will dig a little deeper into Gregson. We’ll go home with the guy for the first time, we’re going to meet his wife, we’re going to learn a little more about his circumstances at home and his family. We get there through the lens of a case, but it’s especially great to flush him out a little bit and see where he comes from. The goal, of course, is to do more stories like that with Bell as we get deeper into the season.

Will Sherlock’s relationship with his new sponsor, Alfredo, play a significant role this season?

So far, we are into our eighth [episode] and we haven’t quite cracked a return for Alfredo yet, even though we love the actor [Ato Essandoh] and we love the character. I wouldn’t be surprised if he makes his way back, we just haven’t had a story for him yet. But I hope we get there.

You already have a slew of guest stars set for the first few episodes. Can you talk about some of them and how they factor into Sherlock’s story?

Rhys Ifans had been the model for our Mycroft for some time. You fantasize and cast the parts in your head so you have a face when you’re trying to write their story, so it was outrageous good fortune that he was available and interested. Inspector Lestrade is played by Sean Pertwee, an actor I had seen in many feature films and British TV series. A year ago I had imagined him playing a certain role in an episode and had reached out but it just didn’t work out. Over our brief hiatus, Jonny reached out to me to see if there were any interesting parts [because] he had a friend in London who’d love to be a part of the show. It turned out that friend was Sean Pertwee. Laura Benanti will play an interesting character from Sherlock’s very distant past in one of the episodes. The first thing I had ever seen Laura in was the Eli Stone pilot with Jonny. She was the sympathetic client in the pilot episode. It was fun for us to get them back together.

Will season two be similar in format to last year, where you’ll have a main villain that runs through much of the season?

We’ve talked about a few things. We don’t have anything set in stone just yet. I can tell you that over the first half of the season we will introduce Mycroft and we will see him again in episodes seven and eight. People who are [introduced] to the world [this season,] we are going to see more of [and] Mycroft would be No. 1 on that list. We would love nothing more than to have Natalie Dormer back as Irene/Moriarty, but she is a very, very popular actor — as she should be. For us it’s a matter of having to work around her Game of Thrones and Hunger Games schedules, so we’re looking ahead and hoping that we can get her back for at least an episode. As we move into the back half, we’re drawn to the idea of somebody who could recur as an antagonist and yet not hit all of the same notes that Moriarty did in the first season.